发明名称 Untethered stylus employing low current power converter
摘要 An untethered stylus, configured to cooperate with a location sensor, includes a coil resonant circuit configured to develop an arbitrary AC voltage in response to a varying magnetic field produced by the location sensor. The coil resonant circuit includes a first capacitor and an inductive coil. A power converter includes a switch circuit having an output coupled to a second capacitor, an input coupled to the coil resonant circuit, and a threshold voltage. The switch circuit facilitates charging of the second capacitor in response to the arbitrary AC voltage and discontinuance of second capacitor charging in response to a voltage across the first capacitor reaching the threshold voltage so as to prevent diversion of a discharging current when the arbitrary AC voltage exceeds the threshold voltage. A stable DC voltage is provided at the output of the switch circuit. The power converter is preferably devoid of a Zener diode.
申请公布号 US8243049(B2) 申请公布日期 2012.08.14
申请号 US20060613633 申请日期 2006.12.20
申请人 VOS MARTIN J.;3M INNOVATIVE PROPERTIES COMPANY 发明人 VOS MARTIN J.
分类号 G06F3/033;G06F3/041;G06K11/06;G08C21/00 主分类号 G06F3/033
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